Congresswoman Ayanna Pressley (center) joined state attorney general candidate Andrea Campbell (right) to celebrate the opening of Campbell’s campaign headquarters on Talbot Avenue in Codman Square before setting off on a door-to-door canvass of voters. State Rep. Russell Holmes (left) joined them for July 30 event. All three are on the ballot this fall. Campbell launched her run for attorney general this year after Maura Healey opted to run for governor.